Registry

Ok well my problem first started with the internet. I have the Google site set so when i open the web it goes straight there. Since the other day the site is now a Smartsearch page.. this i know is something to do with spyware. I have downloaded a few fixes (spysweeper, Adaware) but the page does not go away. As i was still having difficulty with the removal of this smartsearch page i looked for further help on the web. I found a site giving manual instructions on how to remove it. The site said to go into the registry and change some values. Now before today i had no idea how important the registry was and what was. The problem i have is that when i try and open any programs whether it be notepad or "My computer" the internet gets launched and says "page cannot be displayed". Im not sure what i have done and im not sure what i can do. any help would be greatly received..